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- 'use strict';
- // https://github.com/tc39/proposal-iterator-helpers
- var $ = require('../internals/export');
- var call = require('../internals/function-call');
- var aCallable = require('../internals/a-callable');
- var anObject = require('../internals/an-object');
- var isObject = require('../internals/is-object');
- var getBuiltIn = require('../internals/get-built-in');
- var getIteratorDirect = require('../internals/get-iterator-direct');
- var closeAsyncIteration = require('../internals/async-iterator-close');
- var Promise = getBuiltIn('Promise');
- var $TypeError = TypeError;
- $({ target: 'AsyncIterator', proto: true, real: true, forced: true }, {
- reduce: function reduce(reducer /* , initialValue */) {
- var record = getIteratorDirect(this);
- var iterator = record.iterator;
- var next = record.next;
- var noInitial = arguments.length < 2;
- var accumulator = noInitial ? undefined : arguments[1];
- var counter = 0;
- aCallable(reducer);
- return new Promise(function (resolve, reject) {
- var ifAbruptCloseAsyncIterator = function (error) {
- closeAsyncIteration(iterator, reject, error, reject);
- };
- var loop = function () {
- try {
- Promise.resolve(anObject(call(next, iterator))).then(function (step) {
- try {
- if (anObject(step).done) {
- noInitial ? reject($TypeError('Reduce of empty iterator with no initial value')) : resolve(accumulator);
- } else {
- var value = step.value;
- if (noInitial) {
- noInitial = false;
- accumulator = value;
- loop();
- } else try {
- var result = reducer(accumulator, value, counter);
- var handler = function ($result) {
- accumulator = $result;
- loop();
- };
- if (isObject(result)) Promise.resolve(result).then(handler, ifAbruptCloseAsyncIterator);
- else handler(result);
- } catch (error3) { ifAbruptCloseAsyncIterator(error3); }
- }
- counter++;
- } catch (error2) { reject(error2); }
- }, reject);
- } catch (error) { reject(error); }
- };
- loop();
- });
- }
- });
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